Denhardt's Solution

Blocking agents prevent non-specific binding of ligands to surfaces. In molecular biology, blocking agents are used to suppress non-specific binding in Southern blotting, Northern blotting, and Western blotting. Common blocking agents for nucleic acid hybridization include Denhardt's Solution and BLOTTO. In most procedures, membranes containing target molecules are typically incubated with blocking solution for 1–2 hours before probe addition, which effectively reduces background hybridization.

Denhardt's Solution (50X) consists of Ficoll 400, PVP, BSA, and other components. It is sterile-filtered and mainly used for RNA hybridization, single-copy sequence DNA hybridization, and hybridization with DNA immobilized on nylon membranes.